Evaporator tank and method



Ocut. 29, 1929. J, Q, CARREY 1,733,400

EVAPORATOR TANK AND METHOD Oct. 29, 1929. J, 0, CARREY EVAPORATOR TANK AND METHOD sheets-sheet 2 Filed May l0, 1926 jkl/winx Jip,

do/a/z r/'ey Oct. 29, 1929. 1 o, CARREY 1,733,400

EVAPORATOR TANK AND METHOD Filed May lO, 1926 4 Sheets-Sheet 5 #6 @1M 4f M642 47 J5 a f ff 77 75 @Ue/@Zar ct. 2.9, 1.929. I A J. o. cARREY 1,733,400

EVAPORATOR TANK AND METHOD 4 Sheets-Sheet 4 Filed May 10. 192e J6 J7 da/a 0. Ca/rr 7 Patented Oct. 29, 1929 UNITED STATES PATENT OFFICE JOHN CARREY, OF ST. LOUIS, MISSOURI, ASSIGNOR TO C. & C. ENGINEERING CO., INC., 0F ST LOUIS, MISSOURI, A CORPORATION 0F MISSOURI EVAPORATOR TANK AND METHOD Application lled May 10, 1926.

This invention relates to new and useful improvements in evaporator tanks for refrigerating systems and to a novel method of evaporating the refrigerant in said tank.

The obj ects of the invention are to simplify the construction and operation of refrigerating systems and to provide a more efiicient and inexpensive expansion or cooling unit for such systems.

Further obj ects of the invention are to provide a tank having a mass of cold absorbent or storing material loosely arranged therein which form interstices or passages through which the refrigerant which is released in the lower end of said tank is forced to pass during the evaporating process, thereby absorbing the heat contained in said material and storing cold therein so that the tank will maintain a low degree of temperature for a definite length of time after the evaporation of the refrigerant has ceased.

Other objects of the invention are to provide a layer of oil at a predetermined level in said tank so as to cause the gaseous refrigerant to pass therethrough thereby preventing too rapid evaporation of the refrigerant and to provide suitable filtering means for separating the oil from the refrigerant whereby only refrigerant is allowed to reenter the circulatory connections of the refrigerating system.

Still other objects of the invention are to provide suitable means for controlling the admission of refrigerant into said tank, said means being operable in correlation with the pressure created by the evaporation of said refrigerant in said tank, and to provide simple and efficient method for effecting the transfer of heat in said tank.

With these and other objects in view, my invention consists in certain novel features of construction and arrangement of parts, hereinafter more fully described and claimed, and illustrated in the accompanying drawings, in which- Figure 1 is a diagrammatic view of a refrigerating system of the type using a compressor unit for compressing the refrigerant and releasing such refrigerant in a suitable cooling unit.

Serial No. 108,075.

Figure 2 is a vertical cross section through an .evaporator tank.

Figure 3 is a horizontal cross section online 3 3 of Figure 2.

Figure 4 is a horizontal cross section taken on line 1-4 of Figure 2.

.Figure 5 is a horizontal cross section taken on line 5--5 of Figure 2.

Figure 6 is a top plan view of the tank showing the supporting means therefor in cross section. Y

Figure 7 is a vertical cross section through the modified form of evaporator tank.

Figure 8 is a horizontal cross section: taken on line 8 8 of Figure 7.

Figure 9 is a side elevational view of the detachable member of the supporting means.

Figure 10 is a front elevational view of the same, partly broken away.

Figure l1 is a front elevational view of another modified form of evaporator tank.

Figure 12 is a vertical cross section, partly broken away, of the evaporator tank shown in Figure 11.

Figure 13 is a fragmental sectional view of the lower portion of the tank. Y

Figure 14 is a top plan view of the member shown in Figure 15.

Figure 15 is a vertical cross section through one of the members utilized in the construction of the last-mentioned modified form. K

Figure 16 is a vertical cross section through the cooperating member used in the construction of the modified form.

Figure 17 is a detail cross section showing the method of joining the marginal edges of said members together.

Figure 18 is a detail cross section showing the adjustable mounting of valves of the modified tank.

In the operation of refrigerating systems of the expansion type, it has been general practice to allow the refrigerant to eX- pand in an expansion coil which was placed in a brine tank, the latter being located in the cooling compartment of the refrigerator. In some instances, the coil itself was placedin such cooling compartment and the use of the brine tank was dispensed with. Such y construction is expensive and calls for a 100 great number of joints and connections which render it very diflicult to eliminate leakage of the refrigerant.

In the present invention, the refrigerant is admitted into an evaporator tank and means are provided therein to spread the refrigerant throughout the tank and which will store the cold so as to prevent too rapid changes in the temperature of the tank, and the consequent frequent stopping and starting of the operating mechanism of the refrigerator system. The flow of the refrigerant into the tank is automatically controlled either by a suitable oat mechanism of a pressure operated device and additional means are provided, operable by the pressure created by the evaporation of refrigerant in said tank, for opening and closing the electric circuit of the motor utilized to operate the compressor of the system, or in otherwise disabling the refrigerating system.

Referring by numerals to the accompanying drawings, and particularly to Figure 1, 10 indicatesv a compressor operated by a motor 11 and connected at the high pressure side by a connection 12 to `a condenser coil 13 which delivers the condensed refrigerant through a connection 13 to an evaporator tank 14. The gaseous refrigerant is reconducted by a connection 15 to the low pressure side of compressor 10. Evaporator tank 14 is in the form of a container 16, the upper end of which is closed by flexible wall member 17 which is reinforced by an auxiliary cover 18 having a bulged-out central portion which provides clearance between said portion and the central portion of flexible wall member 17. The bulged-out portion is provided with openings 18a and a centrally located boss 19. A. tubular member 20 is arranged vertically and centrally in container 16, and the upper end thereof which terminates a suitable distance below the iexible wall 17 is closed by a cap v21 having connected thereto the discharge end of condenser connection 13 and provided with a discharge opening 22 through which the refrigerant is admitted to said tubular member 20. The lower end of the latter terminates in an enlarged end 24 provided in its its top wall with openings 25 through which the refrigerant is discharged into the tank 16.

A {ioat 26 is arranged in tubular member 20 and is provided at its upper end with a needle valve 27 which is adapted to close opening 22 and the lower end of Said valve is provided with an extension 28 which is slidably arranged in a bearing 29 for guiding said float. Container 16 is filled up to a predetermined height with loose mass of material such as pebbles 30 of a certain size which serve to spread the refrigerant throughout the container and provide a mass from which the heat is absorbed during the evaporation of the refrigerant. therebv serving to maintain the tank cold for a long period of time after the evaporation of the refrigerant has been stopped. A certain amount of oil is arranged in the container at a predetermined level, as indicated at 31, and said oil serves to check the evaporation of the refrigerant in order that the evaporation will notrtake place too rapidly.

A layer of cotton or other line fibrous material 32 is arranged above the mass 30 and serves to separate the oil from the refrigerant. This layer of. cotton is preferably contained between screens 33 so as to provide for easy removal and replacement of said filtering mass in the container. The liquid refrigerant upon being admitted to tubular member 20 through connection 13a descends into the enlarged end 24 and enters, through openings 25, the lower end of container 16.

When the level of the liquid refrigerant reaches a predetermined height, float 26 is operated, thereby closing discharge opening 22 in cap 21 and stopping the flow of refrigerant into said tank. The refrigerant contained in the tank evaporates partly due to the volatile qualities thereof and partly to the suction produced in the upper end of said container by the return connection 15 and ascends, upwardly through the interstices formed between the pebbles 30, and then passes through the filtering material 32 and is then drawn back to the compressor through connection 15.

During the evaporation'of the refrigerant, the heat contained in the mass 30 is absorbed by the refrigerant so that said mass and tank 16 are maintained at a predetermined low temperature and absorb the heat from the refrigerator in which said tank is placed.

When the level of the refrigerant falls below a predetermined height, iioat 26 is lowered, thereby opening discharge port 22 so that a Ynew charge of liquid refrigerant can be admitted to the tank. When the evaporation of the refrigerant reaches a predetermined degree, a pressure is created in chamber 34, which pressure operates flexible wall member 17 causing it to move upwardly. This upward movement of member 17 actuates stem 35 which is slidably arranged in boss 19 and has its upper end connected to one end of a lever 36 which is fulcrumed at 37 and has its opposite end bent downwardly as indicated at 38. This end 38 carries contact 39 having electrical connection 40 and said Contact 39 is adapted to engage contact member 41 which is connected by an electrical connection 42 to a suitable mechanism (not shown) for operating a switch controlling the circuit of motor 1l, whereby said circuit is closed. In this manner, the compressor 10 is rendered operative and Will remain so until the pressure in chamber 34 falls below a predetermined degree, whereupon flexible wall member 17 will collapse, actuating lever 36 in the opposite direction so that contact member 39 is disengaged from contact member 41 thereby actuating the switch mechanism to open the electric circuit of motor 11 and render the .compressor 10 inoperative. In this manner all danger of excessive pressure being built up in chamber 34 is thereby avoided and the tank is renderedy entirely automatic in operation. A small spring 45 is preferably used to assist the flexible Wall 17 in returning lever 36 to disengaged position.

In the form shown in Figures 7 and 8, instead of'using a float mechanism for controlling the admission of refrigerant to the tank, a pressure-operated device 46 of the type disclosed in my copending application fileg August 25, 1926, Serial No. 131,459, is use The evaporator tank may be of any form,

being shown of cylindrical shape in the present instance. The upper end ofthe tank is provided with a horizontally disposed annular flange 16a which is adapted to be engagedby the hooked lower ends 47 of members 48 and the latter are adapted to be secured to the ceiling of the tank compartment and serve to suspend the tank therein. One of the members 48, preferably 'the front one, may be formed detachable as shown in Figure 9 so as to permit easy removal of the tank from the compartment. This member 48 is provided in its upper end with horizontally disposed lateral flanges 49 which are designed to be received in recess 50 horizontallydisposed in a bracket 51 which is secured to the ceiling of the tank compartment. A lock member 52 is pivotally fixed at 54 to bracket 51 and serves to lock member 48* against accidental removal.

In the form shown in Figures 11 to 17, an

` evaporator tank 55 is disclosed, said tank consisting of a series of intercommunicating members 56 having flexible walls so as to render the tank expansible in axial direction. Each member 56 consists of two complementary sections 57,-preferably formed of pressed sheet metal having annular flanges 58, the edges of which are adapted to be welded t0- gether as indicated at 60 to form a fluid-tight chamber 61. The central portion of each member 57 is provided with a tubular axial extension 62 and the extension of one member 57 is adapted to engage and communicate with the extension of the adjacent member so as to provide communication between theA members 48, as shown in Figure 11. Tubular extension 64 has formed therein a chamber 66 from which leads connection 15. The downwardly presented tubular extension' 62 of the lowermost member 56 has secured thereto tubular extension 67 of a fitting 68 and the latter is formed with a chamber 69 into which leads the discharge end of connection 13a. Fitting 69 is provided with 0 positely disposed valve seats 70 and 71 in W ich are adapted to be seated oppositely disposed valves 72 and 7.3, respectively, carried by the lower end of a stem 74. Stem 74 extends upwardly through all of the members 56 and the upper end of said stem is rigidly secured in casting as indicated at 75, being preferably screw-seated therein. Fitting 68 is provided in its lower end with an opening 76 closed by a removable plug 77, and stem 74 and valves 72 and 7 3 may be adjusted in position through said opening.

A disk or baille plate 78 is arranged in eachv chamber 61, preferably equidistant from members 57 and is of less diafneter than the inner diameter of joint edges 59 so as to provide a clearance for the passage of refrigerant. These disks are held in position by tubular sections or sleeves 79 which are slipped on stem 74 and serve to space saiddisks from each other to maintain them in proper position in chamber 61.

In order to permit adjustment of valves 72 and 73 independently of each other and of stem 74. a sleevel 80 is screw-seated on said stem and is exteriorly threaded to receive said valves. Thus by turning said sleeve in the proper direction, upper valve 72 may be first adjusted to seat itself in seat and close opening 81 extending between said valve seats when the tank 55 is contracted to a predetermined degree due to thefall of temperature. This opening 81 will also be closed and communication between chamber 69 and sleeve 67 interrupted when tank 55 expands beyond a definite lpoint on account of the pressure created in tank 55. Thus it will be seen that the tank 55 will operate only within a definite range and this range of operation may be varied by the adjustment of valves 72 and 73.

Each chamber 61 is preferably filled with a suitable fibrous material and the lowermost chamber 61 is provided with a perforate washer 83 which prevents said materialA from entering the tubular extension of the lowermost member 56. at the same time serving as a support for the lowermost sleeve section 79.

The lower end of tank 14 may be provided with a suitable rack 84 depending therefrom and adapted to support a series of trays 85 containing water for making ice cubes or food which it is desired to freeze.

The liquid refrigerant upon being admitted into the tank boils or evaporates and rises upwardly to the upper end of the tank. The

pressure created in the tank by the gaseous refrigerant causes expansion ofthe tank or part thereof, which, when it reaches a predetermined degree, is instrumental in energizing the pumping mechanism, thereby withdrawing the gaseous refrigerant from the tank, until the pressure in the tank falls below the desired degree whereupon said pumping mechanism will be again rendered inoperative and the cycle of operation will be repeated.

By expanding the refrigerant directly in the tank, the use of expansion coils and brine or cooling tanks is dispensed with, thereby cheapening the cost of the apparat-us and providing a more eliicient construction as the number of joints and connections are eliminated and the danger of leakage of the refrigerant is considerably reduced.

The tank is so constructed that it can be made of pressed sheet metal at ver low cost and easily assembled together. y providing a removable hook 48, the tank can be readily removed from and replaced in the tank compartment of the refrigerator, without requiring a great deal of work or time.

While I have shown and described the preferred forms of construction of my improved tank, it will be readily understood that various changes in the construction and arrangement of parts of my tank may be made and substituted for those herein shown, without departing from the spirit of my invention as set forth in the appended claims.

I claim:

1. An evaporator tank for refrigerating systems comprising a sealed container, a refri gerant releasing member arranged near the lower end of said container, a loose mass of heat transfer material disposed in said container and adapted to be traversed by said refrigerant whereby the heat is transferred from said mass to said refrigerant, a layer of ltering material arranged yin said container above said mass of heat transfer material for permitting only gaseous refrigerant to enter the upper end of said container, and connections leading from the upper end of said container for conveying the gaseous refrigerant therefrom.

2. An evaporator tank for refrigeratlng systems comprising a sealed container, a refrigerant releasing member arranged near the bottom thereof, a loose mass of heat transfer material disposed in said container and surrounding said heat refrigerant releasmg member whereby the refrigerant released thereby is brought into surface contact with said mass, thereby extracting heat therefrom,

a layer of filtering material arranged above said mass for separating foreign substances from the refrigerant and permitting only the latter to enter the upper end of said container, a layer of oil arranged in said container between said refrigerant releasing member and mass to said refrigerant, a yieldin wall portion formed in said upper wall o said container and expansible by the pressure created in the chamber of the upper end of said container by the evaporation of the refrigerant, and means operable by said yielding wall portion for enabling or disabling said refrigerating system.

4. An evaporator -tank for refrigerating systems comprisinga sealed container, a refrigerant releasing member arranged near the bottom thereof, a loose mass of4 heat transfer material disposed in the lower part of said container and adapted to be traversed by theJ refrigerant whereby the heat is transferred from said mass to said refrigerant, a yielding wall portion formed in one of the walls of said container spaced above the level of said heat transfer material and expansible by the pressure created in the chamber of said container by the evaporation of the refrigerant, and an electric switch operable by said yielding Wall portion for controlling the compressor of said refrigeratingsystem.

5. An evaporator tank for refrigerating systems comprising a sealed container. a refrigerant releasing member arranged near the bottom thereof, a loose mass of heat transfer material disposed in said container in spaced relation with the upper wall thereof thereby forming a pressure chamber, said loose mass of heat transfer material being adapted to be traversed by the refrigerant whereby the heat is transferred from saidv mass to said refrigerant, a yielding wall portion disposed in said chamber and formed in one of the walls of said container and expansible by the pressure created in said chamer by the evaporation of the refrigerant, a lever pivotally mounted on said container and operable by said yielding wall portion, and a switch mechanism cooperating with said lever and controlling the electric circuit of said refrigerating system.

6. An evaporator tank for domestic refrigmember and said intakeconnection whereby the admission of refrigerant to said tubular connection is controlled in predetermined relation with the level of the refrigerant in said tubular member, a refrigerant discharge member secured to the lower end of said tubular member and extending annularly therefrom and provided with apertures in its upper wall for releasing the refrigerant throughout the lower end of said container, a mass of heat transfer material loosely arranged in said container exteriorly of said tubular member for effecting the distribution of the refrigerant throughout the container and providing a large mass for transferring heat, and a discharge connection for conveying the gaseous refrigerant from the upper end of said container.

7. An evaporator tank for household refrigerating systems comprising a sealed container, a stationary tubular member disposed longitudinally in said container, a refrigerant y intake connection connected to the upper end of said tubular member, a fioat valve arranged in said tubular member for controlling the communication between said tubular member and said intake connection whereby the admission of refrigerant to said tubular connection is controlled in predetermined relation with the level of the refrigerant in said tubular member, a refrigerant discharge member secured to the lower end of said tubular member and extending annularly therefrom and provided with apertures in its upper wall for releasing the refrigerant throughout the lower end of said container, a mass of heat transfer material loosely arranged in said container and completely filling the same and surrounding said refrigerant discharge member for effecting the distribution of the refrigerant throughout the container and providing a large mass for trans' fer-ring heat, a discharge connection for conveying the gaseous refrigerant from the upper end of said container, and a layer of filtering material disposed between said mass of heat transfer material and the discharge connection forseparating foreign substances from said refrigerant.

8. An evaporator tank for refrigerating systems comprising a sealed container of suitable proportion to provide the necessary refrigerating area, a tubular memberdisposed longitudinally in said container, a refrigerant intake connection connected to the upper end of said tubular'member, a fioat valve arranged in said tubular member for controlling the communication between said tubular member and said intake connection whereby the admission of refrigerant to said tubular connection is controlled in predetermined relation with the level of the refrigerant in said tubular member, a refrigerant discharge member secured to the lower end of said tubular member and provided with apertures in its upper wall for releasing the refrigerant throughout the lower end of said container, a mass of heat transfer material loosely arranged in and completely filling the lower portion of said container for effecting the distribution of the refrigerant throughout the container and providing a large mass for heat exchange, said mass of material being excluded from said tubular member, a discharge connection for conveying the gaseous refrigerant from the upper end of said container, a layer of filtering material disposed between said mass of heat transfer material and the discharge connection for separating foreign substances from said refrigerant, anda layer of oil arranged between said mass of heat transfer material and said filtering material for preventing too rapid evaporation of said refrigerant.

9. An evaporator tank comprising a sealed container of suitable dimensions toprovide the necessary refrigerating surface area, a refrigerant releasing and distributing material arranged near the bottom of said container and substantially coextensive therewith, said releasing member consisting of a hollow disk shape casing closed on top and bottom and provided with discharge openings in its upper end, a tubular connection arranged longitudinally in said container and having its lower end opening into said casing, a refrigerant inlet connection connected to the upper end of said tubular connection and operable to admit at predetermined periods of time liquid refrigerant into said tubular connection and said releasing member, a layer of pebbles arranged in said container surrounding said releasing member and extending a suitable distance thereabove, said pebbles providing a large mass of heat absorbing and transferring material whereby the heat transferred from the tank to the refrigerant is thereby facilitated and the tank is maintained cold for a suitable length of time thereafter, a layer of filtering material disposed above said layer of pebbles for filtering the refrigerant, and a discharge connection arranged in said contaillier above the layer of said filtering materia In testimony whereof I hereunto afx my signature this 27th day of April, 1926.

- JOHN O. CARREY. 

